Many injectable drugs are packaged and distributed in hypodermic syringes that will eventually be used to administer the drug to the patient. The syringe is the low cost, efficient, sterile instrument of choice for delivering liquid drug through a hypodermic needle. The hypodermic syringe also can be an excellent storage device for drug placed in it by a pharmaceutical manufacturer or hospital pharmacy.
Syringes may also prove useful for distributing and administering drugs even where a hypodermic injection is not desired. Delivering a therapeutic liquid as a spray through the nasal passageway is preferred to deliver certain therapeutic liquids under certain conditions. There have been several proposed devices to make syringes useful as nasal sprayers.
U.S. Pat. No. 5,601,077 to Imbert discloses a nasal syringe sprayer for discharging the liquid contents of the syringe in a spray through the nasal passages. However, the use of that device is limited to pre-stored, liquid stable drugs. That is, the sprayer of the patent cannot be used with drugs that need to be maintained in powder or lyophilized form and reconstituted just prior to intake. Additionally, the sprayer tip of that patent does not allow an individual to load the syringe with a liquid mediation from a standard vial since the nasal spray nozzle cannot be inserted into such vials to extract the contents of the vial for loading the syringe.
U.S. Pat. No. 4,767,416 to Wolf et al. discloses a flexible, removable spray nozzle for a syringe. The spray nozzle may be attached directly to a luer fitting of a syringe or may be adapted to fit over and attached to a hypodermic needle secured to the luer fitting. In either case, the spray nozzle fits onto the syringe in order to prevent back flow and leakage of the liquid at the attachment of the spray nozzle to the syringe. One shortcoming of the device is that the nozzle does not prevent unpressurized liquid from flowing through the opening at the tip of the spray nozzle.
In view of the shortcomings and drawbacks of currently available or proposed systems, it is desirable to provide a removable spray nozzle for use with hypodermic syringes that provides a leak-free seal and prevents unpressurized liquid from flowing out the opening at the spray nozzle.